Xerographic registration guide



Feb. 3, 1959 R. w. GUNDLACH XEROGRAPHIC REGISTRATION GUIDE 2Sheets-Sheet 1 Filed Aug. 29, 1955 Fi.B

INVENTOR. ROBERT W. GUNDLACH FMASHM ATTORNEY Feb. 3, 1959 w, GUNDLACH2,871,819

XEROGRAPHIC REGISTRATION GUIDE Filed Aug. 29, 1955 2 Sheets-Sheet 2 4*.V q J 5 INVENTOR.

ROBERT W. GUNDLACH ATTORNEY XERUGRAPHIC REGISTRATION GUIDE Robert W.Gunillach, Spencerport, N. Y., assignor to Haloid Xerox Inc., Rochester,N. Y., a corporation of New York Application August 29, 1955, Serial No.531,052 6 Claims. (Cl. 118-637) This invention relates to the field ofxerography and, particularly, to improvements in apparatus for obtainingaccurate registration of a xerographic powder image with the supportmaterial to which it is to be transferred.

in a general application of the process of xerography, as disclosed inCarlson Patent 2,297,691, issued October 6, 1942, a. xerographic platecomprising a coating of photoconductive insulating material on aconductive backing is given a uniform electric charge over its surfaceand is then exposed to the subject matter to be reproduced, usually byconventional photographic techniques such as by camera, projection, orcontact exposure, depending upon the type of application. This exposuredischarges the plate areas in accordance with the light intensity whichreaches them, thereby creating an electrostatic latent image on or inthe plate coating. Development is effected with a finely dividedmaterial, such as an electroscopic powder, which is brought into contactwith the coating and is held thereon electrostatically in a patterncorrespondiug to the electrostatic latent image. Finally, the powderimage is transferred to a suitable base, such as paper, and. is fixedthereon by fusion or by use of a solvent, in accordance with the type ofdeveloping material employed.

In the practice of the art of xerography, as in any graphic artsprocess, the registration of the copy to be reproduced with the supportmaterial on which it is to appear is of prime importance from thestandpoint of appearance, convenience of viewing, and, in certaininstances, to permit the subsequent addition of variable information ona standard form. In automatic xerographic machines, accurateregistration is obtained in a variety of ways that are comparable tothose employed in conventional printing processes. However, in manualxerographic processes, accurate registration is largely dependent uponthe skill of the operator. In practice, the most critical registrationproblem arises at the time of transfer of the xerographic powder imagefrom the xerographic plate to its ultimate support material. At thispoint, the powder image is held on the xerographic plate merely byelectrostatic attraction and, thus, is subject to being smeared ifcontacted by any external substance. Furthermore, the photoconductivesurface of the conventional xerographic plate is rela tively soft andcan readily be marred or scratched by the use of mechanical registrationguides. Finally, because of the sensitive surface of the photoconductiveplate, it is not convenient to form a grid structure thereon to assistan operator in aligning the support material therewith. As a result, theoperator is obliged to align the support material with the powder imageby eye in most instances. In order to avoid smearing the xerographicpowder image or damaging the photoconductive surface of the plate, anoperator is required to attain a high degree of skill to effect theproper performance of his duties.

The principal object of the present invention is to provide an improvedregistration guide for use in xerographic processes. A further object isto provide a hired States Patent xerographic registration guide tominimize the possibility of smearing xerographic powder images duringtransfer operations. A further object is to provide a xerographicregistration guide of a construction to minimize the possibility ofdamage to the photoconductive surface of the xerographic plate duringuse. A further object is to provide a xerographic registration guide toobtain accurate alignment of a Xerographic powder image formed on axerographic plate with the support material to which I the powder imageis to be transferred.

These and other objects of the invention are attained by means of aregistration guide for positioning flexible image support material withreference to a xerographic powder image formed on a xerographic plateassembly wherein the plate assembly comprises a conductive plate membersupported in a rectangular frame member, said plate member beingprovided with a photoconductive coating on the central area thereof andwhich may have an uncoated marginal area separating the coated area fromthe frame member, said registration guide comprising a pair oflongitudinal base members spaced substantially to abut the innerlongitudinal edges of the frame member, each base member being of alesser width than the marginal area separating the coated area of theplate member from the inner edges of the frame member, a longitudinalguide member for support material mounted on the upper surface of theplatform member and a lateral guide member for support material mountedon the upper surface of the platform member normal to the longitudinalguide member. Briefly, the registration guide of the invention comprisessubstantially parallel base members that are spaced to fit Within theside walls of a conventional xerographic plate and serve to support asupport material positioning platform above and out of contact with thexerographic powder image formed on the xerographic plate, said platformbeing provided with a longitudinal positioning guide for the supportmaterial and a lateral support material positioning guide normalthereto.

A preferred form of the invention is disclosed in the appended drawings,in which:

Fig. 1 is an isometric view of a xerographic processing machine withwhich the invention may be used;

Fig. 2 is an isometric view of a xerographic camera;

Fig. 3 is an isometric view of the registration guide of the invention;

Figs. 4 and 5 are isometric views illustrating operational steps in theuse of the xerographic registration guide of the invention in. thetransfer of a xerographic powder image to a support material.

Before considering the specific details of the xerographic registrationguide of the present invention, it is preferred briefly to summarize thexerographic processing equipment with which such guide is intended foruse. A conventional form of xerographic plate assembly currently in widecommercial use is disclosed in Mayo Patent 2,619,418, issued November25, 1952. A device of this type usually comprises a xerographic platethat is secured in a rectangular plate holding frame having longitudinalside members 42 (see Figs. 4 and 5) and lateral side members 44 that areprovided with suitable recessed grooves to accommodate a dark slide toshield the plate from light during its normal use and to protect thesurface of the plate from damage when the plate assembly is stored.graphic plate may be formed of various compositions and in varioussizes, the type most commonly used at present comprises a conductivemetallic backing plate 46 having a surface coating of photoconductivematerial 48 wherein the exposed surface of the backing plate constitutesan area that is approximately 10%" wide by 15% long, and thephotoconductive coating Fatented Feb. 3, 1959- Although the xero- 1;formed thereon covers the entire central area of the platewith theexception ofan uncoated marginal area 50 adjacent the inner edges of therectangular frame member. The marginal area is usually on the order of%"in width and extends completely around the photoconductive area,thereby leaving a usable photoconductive area of approximately 9 x 14'.it is to be understood that the above-mentioned dimensions are purelyillustrative of a conventional type of apparatus and-are not to beconsidered in a limiting sense in connection with the present inventionsince is apparent that such plate assemblies may be made in any desiredsize and may or may not'be provided with the uncoated marginal area, asdesired.

In conventional xerographic practice, the charging, developing, andtransferring operations are usually carried out: in a xerographicprocessing device of the type shown in Fig. 1 which illustrates a XeroXProcessor Model D manufactured by The Haloid Company, of Rochester, NewYork; This device is an adaptation of that disclosed in Sahel et al.Patent 2,600,580, issued June 17, 1952, and includes a charging andimage transferring unit 1, a developing unit 2, and a storage unit 3.The charging and transferring unit includes a support for aXerographic'plate assembly onto which the xerographic plate assembly maybe inserted through a slot 4. A corona discharge device is mountedwithin the unit for applying electrostatic charge to the surface of theplate assembly. The charging device is usually in the form of adischarge electrode extending laterally across the machine and ismounted for longitudinal movement over the face of the plate by asuitable lead screw and cross head mechanism. The discharge electrodemay be energized by means of a three position switch 5 to apply eitherpositive or negative corona to the surface of the plate. Automaticcontrol of the charging mechanism may be had by means of a switch 6which concomitantly energizes the electrode and initiates the operationof the lead screw and crosshead mechanism to cause the electrode totraverse the entire surface of a plate assembly that has been insertedin slot 4. The developing unit of the processor may include one or twotrays 8 each containing an electroscopic powder or developing agent,depending on the type of development that is to be effected. Eachdeveloping tray is mounted on extensible brackets whereby the tray maybe pulled forwardly to a position in which it can be rotated aboutsuitable pivots without interference with the remainder of the machine.When so positioned an exposed xerographic plate assembly may be clampedto the developing tray and developed by cascade, in conventional manner.The storage unit of the processor includes an upper storage bin forholding xerographic plate assemblies. The plate assemblies are insertedinto the bin through an upper slot 9, and may be withdrawn from the binthrough a slot 14 The lower portion of the storage area includes astorage bin for paper or other support material to which the xerographicpowder image may be transferred. The support material is withdrawn fromthe bin through a slot 11 when urged forwardly by a suitable impelleractuated by a handle 12. A hinged cover 13 is provided to enclose thecharging and developing units when the apparatus is not in use.

In order to form an electrostatic latent image of a subject to bereproduced on the photoconductive layer of a xerographic plate assembly,the plate assembly is exposed in a camera which may be of the typeillustrated in Fig. 2, namely a XeroX Camera No. 4, manufactured by TheHaloid Company, of Rochester, New York. Essentially, such a cameracomprises a base frame 15, a copyboard 16, mounted at one end thereof,and a camera generally designated by reference character 17. The cameraassembly comprises the conventional lens mount 18, extensible bellows1%, and plate supporting frame for supporting a ground glassfocusingscreen or a xerographic plate assembly in the focal plane of thecamera. Thecamera elements may be variously positioned on the base frameby means of adjusting screws 21 and 22 to effect any desired enlargementor reduction of the copy to be reproduced. Suitable lights 24 arearranged on the frame assembly for illuminating the copyboard undercontrol of a timing switch 25.

In order to obtain accurate registration of subject material on thexerographic plate assembly, the camera is adjusted at installation sothat grid markings 26 that are formed on the copyboard are made tocoincide with similar markings formed on the ground glass focusingscreen. When the proper adjustments are established, any subjectmaterial that is centered on the copyboard with reference to gridmarkings 26 will have its image projected to be similarly centered onthe xerographic plate assembly when a plate is exposed. Rotationalregistration of support member 2% with reference to grid markings 26 maybe eifected by means of levelling screws 27.

In the conventional operation of the above described equipment for thepreparation of xerocopies, a xerographic plate assembly is inserted inslot 4 of the charging unit, the dark slide of the plate assembly isremoved, and switch 6 is operated to cause a uniform electrostaticcharge to be deposited upon the photoconductive surface of the plateassembly. After charging, the dark slide is reinserted in the plateassembly and the entire plate assembly is inserted in plate holdingmount 20 of the camera. Then, assuming that the camera has been properlyfocused with reference to subject material placed on the copyboard, atimed exposure is made to effect the discharge of the electrostaticcharges formed on the exposed area of the xerographic plate. After theexposure is complete, the dark slide is replaced in the xerographicplate assembly and the entire plate assembly is removed from the cameraand is placed face down in juxtaposition to one of the developing traysin the processing unit. The dark slide is again removed from the plateassembly and the plate assembly is clamped to the developing tray anddeveloped by cascading the developing agent in the tray over the surfaceof the plate. By this action, the powder particles of the developingagent are electrostatically attracted to the image portions of theelectrostatic latent image previously formed on the photoconductivesurface of the xerographic plate assembly so that, when development iscomplete, a reverse reading powder particle image or xerographic powderimage of the subject material is formed on such photoconductive surface.

At this point in the conventional process, the operator is obliged toposition a piece of paper or other support material over the xerographicpowder image on the photo conductive surface of the plate assembly andthen, electrostatically transfer the powder image to the surface of thepaper. Normally, this is accomplished by manually aligning the paper orsupport material with the xerographic powder image and superposing thepaper thereon. Thereafter, the xerographic plate assembly with thesupport material superposed on the powder image thereon, is againinserted into slot 4 of the processing unit. This may be effected inconjunction with a concomitant operation of switch 5 whereby the supportmaterial is electrostatically charged as it passes beneath the coronacharging device to attract the xerographic powder image from the surfaceof the plate and cause it to adhere to the under surface of the supportmaterial. Alternatively, the xerographic plate assembly with the supportmaterial superposed thereon may be inserted completely in slot 4 andswitch 6 may then be actuated to effect an automatic application ofcharge to the support material. In either case, the powder image isthereupon electrostatically bonded to the support material and adheresthereto while the support material is-separated from the plate assembly.If desired, the xerographic powder image may subsequently be fused tothe support material by any suitable means whereby a permanent visiblereproduction of the subject material is formed on the support material.

In order to assist the operator in the application and registration ofthe support material to the xerographic plate during the transferoperation, the present invention provides a registration guide which isshown in its preferred form in Fig. 3. Essentially, this guide includesa pair of flat elongated strips or base members 31 arrangedsubstantially parallel to each other and spaced apart a distance suchthat the outer parallel edges of the strips is substantially equal tobut slightly less than the distance between the interior of thelongitudinal side members 42 of the xerographic plate assembly withwhich it is to be used. Fixed to the upper surfaces of base members 31is a platform member 32, having its sides flush with the outer edges ofthe base members. Preferably, the platform member 32'has a taperedforward portion 33 that unites with a corresponding taper on the forwardends of base members 34 to form a continuous downwardly sloping surface.Fixed on the upper surface of platform member 32 is a guide member 35,of substantially rectangular cross section, that is arranged parallel tothe rearward edge of the platform. Fixed to the tapered surface 33 ofthe platform member is a second guide member 36 that is arranged normalto guide member 35. In the particular embodiment shown, base members 31are of a width less than that of the marginal area 50 surrounding thephotoconductive area of a xerographic plate. If desired, guide member 35may be provided with an undercut portion 37 that serves as a fingerholdfor an operator in manipulating the registration guide.

When employed during the transfer step of a Xerocopying process, theregistration guide is positioned as illustrated in Fig. 4, wherein it ispositioned between the longitudinal frame members 42 of the plateassembly and is pulled rearwardly so that the rearward edges of basemembers 31 and platform 32 abut the inner face of the lateral framemember 44 of the plate assembly. As thus positioned, base members 31hold platform 32 above and out of contact with the xerographic imageformed on the plate and, at the same time, provides an ample platform topermit the operator to manipulate the sheet of paper or other supportmaterial on which the xerocopy is to be made. The operator does this bypulling the rearward edge of the paper against guide member 35 and,while retaining this relationship, slides one edge of the paper intocontact with guide member 36. The guide members 35 and 36 are sopositioned on platform 32 that the sheet of support material normallyused in this operation is substantially centered with reference to thexerographic plate and the powder image formed thereon. When a paper orsupport material is thus positioned, the operator allows the remainderof the paper to fall forwardly on the xerographic image. The operatorthen retains the several elements in position and, with the same hand,slides the plate assembly into the charging unit of the processor untilthe leading edge of the support material is positioned beneath thedischarge electrode. At the same time he actuates switch 5 of thecharging unit to apply positive charge to the leading edge of thesupport material. By this means the support material iselectrostatically bonded to the xerographic plate so that theregistration guide may be withdrawn from the plate assembly, asillustrated in Fig. 5. Thereafter, the transfer operation is completedin conventional manner, i. e., the operator slides the plate assemblyinto the charging unit and applies an electrostatic charge over theentire surface of the support material to bond the powder image thereto,then removes the plate assembly from the charging unit and separates thesupport material from the surface of the plate.

By means of the arrangement thus described, there is provided axerographic registration guide whereby paper or other support materialmay be arranged in accurate registration with reference to xerographicpowder image formed on a xerographic plate assembly. In the arrangementshown, the base members contact only the uncoated or unused areas of thexerographic plates and thus cannot mar the photoconductive or usuablearea of the plate. At the same time the guide assembly is maintained outof contact with the xerographic powder image whereby the possibility ofsmearing the powder image is minimized.

Obvious modifications could be made in the above describedinventionwithout departing from the scope thereof. For example, the guide members35 and 36 may readilybe made adjustable with reference to plat formmember 32 to accommodate different size sheets of support material. Byway of example, members 35 and 36 may be provided with tenons that areslidable in grooves formed in the surface of platform 32, or members 35and 36, either individually or as a unit, may be provided with pins thatcoact with any desired set of combinations of holes variously positionedin the surface of platform 32. In either case, suitable indicia may beplaced on the surface of platform member 32 to facilitate positioning ofthe guide members. Additionally, the width of base members 31 may bevaried at will to contact a substantially smaller area of the platesurface in the event the invention is employed in conjunction withxerographic plates having a photoconductive layer over their entireexposed surface, or, since platform 32 is essentially a bridging memberthat is intended to rest on nonsensitive areas of the plate assembly,the side and rearward edges of the platform may be extended slightly andrabbeted on their undersides so that the platform may be supportedentirely by the side and rear rails of the plate assembly. Since manyother changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained herein shall be interpreted in an illustrative sense, and thatthe invention shall be limited only as defined in the appended claims.

What is claimed is:

l. The combination of a xerographic plate assembly and a registrationguide detachably positionable thereon for positioning image supportmaterial with reference to a powder image formed on the xerographicplate assembly wherein the plate assembly comprises a conductive platemember having a photoconductive coating and being supported in arectangular frame member, said registration guide comprising a pair oflongitudinal base members spaced substantially to abut the innerlongitudinal edges of the frame member, a lateral platform memberextend- -ing between and supported on said base members, a longitudinalguide member for support material mounted on the upper surface of theplatform member, and a lateral guide member for support material mountedon the upper surface of the platform member normal to the longitudinalguide member.

2. The combination of a xerographic plate assembly and a registrationguide detachably positionable thereon for positioning image supportmaterial with reference to a powder image formed on the xerographicplate assembly wherein the plate assembly comprises a conductive platemember supported in a rectangular frame member, said plate being rovidedwith a photoconductive coating on the central area thereof and anuncoated marginal area separating the coated area from the frame member,said registration guide comprising a pair of longitudinal base membersspaced substantially to abut the inner longitudinal edges of the framemember, each base member being of a lesser width than the marginal areaseparating the coated area of the plate member from the inner edges ofthe frame member, a lateral platform member extending between andsupported on said base members, said platform member and said basemembers having downwardly tapered forward portions that conjoin to forma substantially plane surface, a longitudinal guide P? member forsupportmaterial mounted on the'upper surface of theplatform member, anda lateral guide member for support material mounted 0I1th upper surfaceof the platform member normal to the longitudinal guide member.

3. The combination of a xerographic plate assembly and a registrationguide detachably positionable thereon for positioning flexible imagesupport material with reference to a powder image formed on theXerographic plate graphic platemember supported in recessed position ina rectangular frame assembly'having longitudinal and lateral sidemembers, said registration guide comprising a platform member forsuperposition on said plate assembly, longitudinal and lateral'members'for guiding support material positioned on said platform, said guidemembers being parallelrespectively with the lateral and longitudinalside members of the plate assembly when the platform member issuperposed thereon, and means positionable by the frame assembly sidemembers for supporting the platform member on said plate assembly inspaced relation to the surface of the plate member.

4. The combination of a Xerographic plate assembly and a registrationguide detachably positionable thereon for positioning flexible imagesupport material with reference to a powder image formed on thexerographic plate assembly wherein the plate assembly comprises aXerographic plate member supported in recessed position in a rectangularframe assembly having longitudinal and lateral side members, saidregistration guide comprising a substantially rectangular platformmember for superposition on said plate assembly, said platform memberhaving a lateral dimension substantially to abut the longitudinal sidemembers of the frame assembly, longitudinal and lateral guide membersmounted on said platform for positioning support material, said guidemembers being parallel respectively with the lateral and longitudinalside members of the plate assembly when the platform member issuperposed thereon, and means for supporting the platform member on saidplate assembly in l spaced relation to the surface of the plate member.

5. The combination of a Xerographic plate assembly and a registrationguide detachably positionable thereon for positioning flexible imagesupport material with reference to a powder image formed on theXerographic plate bly, longitudinal and lateral guide members mounted on"assembly wherein the plate assembly comprises a xero- I3 said platformfor positioning support material, said guide members beingparallelrespectively with the lateral and longitudinal 'side members ofthe plate assembly when theplatform member is superposed thereon, meanspositionable by the frame assemblyside members for supporting theplatform member on said plate assembly in spaced'relation to the surfaceof the plate member, and a plane surface on the platform member inclinedtoward the surface of the plate member when the platform member issuperposed on the plate assembly.

6. in combination with a Xerogra'phic plate assembly including arectangular frame assembly having longitudinal and lateral side members,a conductive plate member supported therein, said plate member beingprovided with a photoconductive coating on the central area thereof andan uncoated marginal area separating the coated area from the sidemembers of said frame assembly, a registration guide, detachablypositioned on said plate assembly, comprising a pair of longitudinalbase members spaced substantially to abut the inner edges of thelongitudinal side members of said frame assembly, each base member beingof a lesser width than the marginal area separating the coated area ofthe plate member from the inner edges of the side members of said frameassembly, a lateral platform member extending between and supported onsaid base members, and longitudinal and lateral guide members mounted onthe upper surface of said platform for positioning support material,said guide members being parallel respectively with the longitudinal andlateral side'members of said frame assembly.

References Cited in the file of this patent UNITED STATES PATENTS 10,432Disston May 24, 1870 662,982 Stevens Dec. 4, 1900 910,330 Wait Ian. 19,1909 1,001,532 Kenyonet al. Aug. 22, 1911 1,430,911 Linebaugh Oct. 3,1922 1,506,990 Multaler Sept. 2, 1924 2,392,031 Denyven et al. Jan. 1,1946 2,619,418 Mayo Nov. 25, 1952 2,620,184 Paley Dec. 2, 1952 2,689,179Walkup et al. Sept. 14, 1954 2,729,195 Belz Jan. 3, 1956 2,741,222Shelton Apr. 10, 1956 2,771,027 Ritzerfeld et al. Nov. 20, 19562,807,232 Hudson Sept. 24, 1957 FOREIGN PATENTS 1,062,549 France Apr.23, 1954

